1. Field of the Invention
The present invention relates to a flat panel display device, and in particular, to a flat panel display device with an improved structure which prevents permeation of harmful material such as moisture or oxygen and degradation of performance of the flat panel display device.
2. Description of the Related Art
FIG. 1 is a cross-sectional view of a conventional flat panel display device, for example, an organic electro-luminescence display panel disclosed in Japanese Patent Publication No. 2001-284041. Referring to FIG. 1, an emission element 20 is formed between partition walls 31 which are extruded on a substrate 11. The emission element 20 includes a first electrode layer 21 as anode injecting holes, an organic film 23 in which light is emitted by the recombination of holes and electrons, and a second electrode layer 27 as cathode injecting electrons. In the organic film 23, light is emitted by the recombination of holes injected from the first electrode layer 21 and electrons injected from the second electrode layer 27, respectively. To this end, it is preferable that the first electrode layer 21 be formed of a material having a high work function and the second electrode layer 27 be formed of material having a low work function. The second electrode layer 27 is highly active and has instable chemical characteristics, and therefore can be easily oxidized or corroded if exposed to outside moisture or oxygen. The organic film 23 having an emission layer also has a degradation of emission due to a change of crystalline structure when moisture or oxygen permeates. In an extreme case, dark spots are formed thereby losing a display function. Therefore, in the conventional art, in order to isolate the organic film 23 and the second electrode layer 27 from the outside, first and second inorganic passivation layers 41 formed of an inorganic compound and a resin capsulation layer 45 therebetween are formed. Since the first and second inorganic passivation layers 41 are stacked over the emission element 20, the permeation of oxygen/moisture through a main face of the first and second passivation layers 41, e.g., the permeation of harmful material via a path R1 is effectively prevented. However, the penetration of harmful material through the side of the exposed first and second passivation layers 41, e.g., the permeation via a path R2 is not effectively prevented.